FIG. 1 illustrates in cross-section a known bearing housing manufactured by SKF Mekan AB and referred to as a SOFN bearing housing for use with oil ring lubricated bearings and FIG. 2 illustrates in a perspective side view the bearing housing shown in FIG. 1. The upper half of FIG. 1 shows the housing with a shaft extending through the housing, whereas the lower half of the drawing shows the housing with a shaft projecting only from the left hand side of the bearing housing.
The bearing housing supports a shaft 1 in a rolling bearing which, in the embodiment shown, is a spherical roller bearing. The bearing housing is split along a substantially horizontal line so that the housing has a lower half 3 and an upper half 4, which are interconnected by bolts. In the lower part of the housing there is a space 5 used as a reservoir for oil. An oil transport ring 6 to be partly immersed is arranged in this space 5. This oil transport ring 6 picks up oil from the reservoir space 5 and lets the oil be thrown off above this space when rotating with the shaft, thereby throwing oil into the bearing surfaces to be lubricated. The lower half 3 of the bearing housing shown in FIG. 1 has a central upwardly projecting, semicircular flange 7 forming the lower half of the seat for the outer ring of the bearing. The inner envelope or peripheral surface of the upper bearing half 4 forms the other half of the bearing seat. The two bearing seat halves thereby form a large-diameter, substantially cylindrical opening through the bearing housing. Due to the positioning of the oil reservoir space 5, this bearing housing is not symmetrical about the axis of the shall 1. In the embodiment shown, the bearing 2 has a taper bore and is mounted on the shaft on a taper sleeve 8.
A lock nut 9 is provided at one side of the bearing for securing the bearing against movement in the axial direction. In case the shaft is not projecting outside the housing on that side, as shown in the lower part of FIG. 1, a disc-shaped end lid 10 is fitted by bolts to the upper and lower bearing housing halves 3, 4. As the end lid 10 also covers and forms a side wall of the oil reservoir space 5, it is of course vital that the lid is securely sealed off at 10a for preventing leakage from the oil reservoir.
On the side of the bearing 2 where the shaft 1 extends out of the bearing housing, i.e. in the upper half of FIG. 1 at both sides of the bearing, a sleeve 11 is mounted around the shaft 1, and each sleeve is fixedly mounted and secured by means of a set screw 12. At its side which is turned towards the bearing, the sleeve 11 is provided with a radially extending flange 13, which at a distance from the sleeve surface has an axially outwardly extending edge 14. A circumferential axial groove 15 is thus provided with its open side facing outwardly away from the bearing.
The side of the housing through which the shaft 1 extends is fitted with an end cover 16. The end cover 16 has an inner envelope or peripheral surface closely fitting around the sleeve 11 and an axially extending shoulder 17 positioned and dimensioned to fit into the groove 15 when the end cover 16 is mounted axially. The inevitable, small slot between the inner envelope surface of the end cover 16 and the outer envelope or peripheral surface of the sleeve 11, and the small spaces between the walls of the groove 15 and the shoulder 17 form together a labyrinth seal which prevents the oil in the bearing housing from leaking out along the shaft, when this oil due to the action of the oil ring 6, splashes around in the housing.
To avoid leakage beyond the labyrinth seal from reaching the outside of the bearing housing, the outer envelope or peripheral surface of the sleeve 11 is provided with a number of circumferential notches 18, positioned between the axially outer side of the end cover 16 and the outwardly extending edge 14 thereof. These notches 18 are positioned at a channel 19 returning any oil which appears there to the oil reservoir space 5.
It can be appreciated that the arrangement with the end cover 16 and an integrated portion thereof forming a part of the labyrinth seal means that the mounting of the bearing housing, particularly at the circled area in FIG. 1, is an operation which must be carried out very carefully.
From FIG. 2, which shows the exterior of the bearing housing illustrated in FIG. 1, it can be seen that the bearing housing has a large number of components. and in particular a large number of bolts 20 for attaching the end lid 10 and/or the end covers 16. In the illustrated embodiment, 9 bolts for each lid or cover are required. The large number of components and the extensive work required for mounting and dismounting at any subsequent maintenance operation means that this known housing is rather expensive and requires a relatively long mounting and dismounting time.